1. Field of the Invention
The present invention relates to vertical blind mechanism having vertically disposed louvers that move laterally and rotably about their vertical axes, and more particularly, to such mechanisms that include a plurality of carriers that are activated through cords and a drive shaft.
2. Description of the Related Art
Applicant believes that the closest reference corresponds to U.S. Pat. No. 3,280,891 issued to Richard J. Eldredge, Jr et al on Oct. 25, 1966. However, it differs from the present invention because Eldredge's device utilizes one drive wheel 93 to cause the louvers to rotate and cable runs 99a and 99b sandwich or run alongside of drive shaft 44, and through drive pulleys 97 and 98. In practice, drive wheel 93 and pulley 97 and 98 are contained within the same assembly in order to have a volumetrically efficient design, as shown in that patent FIG. 8. The present invention provides for two drive wheels, one of them being a dummy wheel, and the drive pulleys for the cable providing the lateral movement are positioned below and in between the downwardly projection of the wheel drives. Also, the assembly and cost of the present invention is simpler and lower since it does not require bearing housing 122, bearing 123 and snap ring 124 at the end of the drive shaft. Finally, the separation of the chain or cable over the two drive shaft is much greater than the separation provided by only one larger drive shaft that occupies a much larger space.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.